Matchplate parts for Aluminum sand cast for Raspberry Pi Zero v 1.3 case

thingiverse

Design for a case for the Raspberry Pi Zero version 1.3 to be sand cast in Aluminum. This design has a "riser" to put the top of the CPU/Memory Package on package in contact with the top of the case. Heat dissipation fins that average 1 mm in width run along the short axis on the top. As this is intended to be sand cast, there is a five degree draft to the vertical surfaces. The two halves of the matchplate have been scaled up to 101% which I understand is the standard shrinkage of Aluminum that is used in sand casting. There are four ninety degree cones on the the pcb standoffs on the heat fin side, and four ninety degree cones on the underside of the bottom piece. The bottom piece should be drilled with a clearance hole for an M2.5 screw. There is enough material to counter sink these holes to allow for the screw to flush mount here. The top piece should have these cones drilled for threading for an M2.5 screw. For aluminum this is usually the 75% thread engagement size. The riser for the cpu/memory package has been extended down to the surface of the board. This is so that it can be machined flat to the correct height. Casting it to the correct height may not result in proper contact with the cpu/memory package. I am including the full sketchup model, as well as STL files of the two case halves in case you want to print it out to check out fitment with the Raspberry Pi Zero. I have not had a chance to try this out. The matchplate is intended to be constructed by printing out the two halves, gluing them together and then gluing the result into some 6mm plywood. Feed back from anyone with sand casting experience would be appreciated. Licensing for commercial use can be negotiated. Update!: Checked with a couple of people with experience in sand casting and aluminum and made some changes to make the resulting match plate work better. Updated description Edit: Fixed a word.